Implement preserving config merge for opencode.

Co-Authored-By: win0na <winnie@winneon.moe>

feat(opencode): config-merge.sh with formatting-preserving JSON merge

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

build(opencode): source config-merge.sh from adapter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

feat(install): use oc_config_merge for opencode.json instead of overwrite

Source config-merge.sh from install scripts for opencode platform so
user keys in opencode.json are preserved on reinstall and update.
Fix in-place merge by writing to a temp file before moving to output.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

adapters/opencode/adapter.sh

@@ -7,6 +7,9 @@
 # opencode expects in the user's vault.
 # =============================================================================
 
+# shellcheck source=adapters/opencode/config-merge.sh
+source "$(dirname "${BASH_SOURCE[0]}")/config-merge.sh"
+
 OC_PLATFORM="opencode"
 OC_FW_DIR="opencode"
 OC_DISPATCHER="AGENTS.md"

adapters/opencode/config-merge.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# =============================================================================
+# adapters/opencode/config-merge.sh — JSON config merge for opencode.json
+# =============================================================================
+# Merges a built opencode.json with an existing one in the vault, preserving
+# user keys and formatting. Only the "mcp" key is managed; everything else
+# belongs to the user.
+#
+# Sourced by the opencode adapter. Requires jq.
+# =============================================================================
+
+# Provide a fallback warn() if scripts/lib.sh has not been sourced yet.
+if ! declare -f warn >/dev/null 2>&1; then
+  warn() { echo "   ! $*" >&2; }
+fi
+
+# oc_detect_indent <file>
+# Detects the indentation unit used in a JSON file.
+# Returns the number of spaces (2 or 4). Defaults to 2.
+oc_detect_indent() {
+  local file="$1"
+  local indent_str; indent_str="$(awk '/^[[:space:]]+[^[:space:]]/ { match($0, /^[[:space:]]+/); print substr($0, 1, RLENGTH); exit }' "$file")"
+  if [[ -z "$indent_str" ]]; then
+    echo "2"
+    return
+  fi
+  case "$indent_str" in
+    $'\t'*) echo "tab" ;;
+    "    "*) echo "4" ;;
+    *)       echo "2" ;;
+  esac
+}
+
+# oc_config_merge <built_file> <existing_file> <output_file>
+# Merges built opencode.json into an existing one:
+#   - If existing doesn't exist → copy built as-is
+#   - If existing is malformed → overwrite with built (with warning)
+#   - Otherwise → merge: our mcp entries overwrite same-name, user keys preserved
+oc_config_merge() {
+  local built="$1" existing="$2" output="$3"
+
+  # Fresh install — no existing file
+  if [[ ! -f "$existing" ]]; then
+    cp "$built" "$output"
+    return 0
+  fi
+
+  # Validate existing file is JSON
+  if ! jq empty "$existing" 2>/dev/null; then
+    warn "Existing opencode.json is malformed — overwriting with built version"
+    cp "$built" "$output"
+    return 0
+  fi
+
+  # Detect indentation from existing file
+  local indent; indent="$(oc_detect_indent "$existing")"
+  local jq_indent
+  case "$indent" in
+    tab) jq_indent="--tab" ;;
+    4)   jq_indent="--indent 4" ;;
+    *)   jq_indent="--indent 2" ;;
+  esac
+
+  # Read our managed MCP entries
+  local our_mcp; our_mcp="$(jq '.mcp // {}' "$built")"
+
+  # Merge: start with existing, overlay our mcp entries.
+  # Always write to a temp file first to support in-place merges (output == existing).
+  local tmp; tmp="$(mktemp)"
+  # shellcheck disable=SC2086
+  jq $jq_indent --argjson our_mcp "$our_mcp" '
+    .mcp = ((.mcp // {}) + $our_mcp)
+  ' "$existing" > "$tmp"
+  mv "$tmp" "$output"
+}

scripts/launchme.sh

@@ -129,6 +129,12 @@ case "$PLATFORM" in
 esac
 PLATFORM_VAULT_DIR="$VAULT_COMPONENTS_DIR"
 
+# Load opencode-specific helpers when building for opencode
+if [[ "$PLATFORM" == "opencode" ]]; then
+  # shellcheck source=adapters/opencode/config-merge.sh
+  source "$REPO_DIR/adapters/opencode/config-merge.sh"
+fi
+
 # ── Migrate legacy manifests (if any) ────────────────────────────────────────
 manifest_migrate
 
@@ -213,7 +219,12 @@ install_dispatcher "$DISPATCHER_SRC" "$DISPATCHER_DST"
 
 # ── MCP / opencode.json ───────────────────────────────────────────────────────
 if [[ -f "$MCP_SRC" ]]; then
-  copy_if_changed "$MCP_SRC" "$MCP_DST"
+  if [[ "$PLATFORM" == "opencode" && -f "$MCP_DST" ]]; then
+    oc_config_merge "$MCP_SRC" "$MCP_DST" "$MCP_DST"
+    info "Merged opencode.json (user config preserved)"
+  else
+    copy_if_changed "$MCP_SRC" "$MCP_DST"
+  fi
 fi
 
 # ── Done ──────────────────────────────────────────────────────────────────────

scripts/updateme.sh

@@ -106,6 +106,12 @@ case "$PLATFORM" in
 esac
 PLATFORM_VAULT_DIR="$VAULT_COMPONENTS_DIR"
 
+# Load opencode-specific helpers when building for opencode
+if [[ "$PLATFORM" == "opencode" ]]; then
+  # shellcheck source=adapters/opencode/config-merge.sh
+  source "$REPO_DIR/adapters/opencode/config-merge.sh"
+fi
+
 # ── Migrate legacy manifests (if any) ────────────────────────────────────────
 manifest_migrate
 
@@ -142,7 +148,12 @@ CLAUDE_MD_CHANGED=$_LAST_CHANGED
 
 # ── MCP / opencode.json ───────────────────────────────────────────────────────
 if [[ -f "$MCP_SRC" ]]; then
-  copy_if_changed "$MCP_SRC" "$MCP_DST"
+  if [[ "$PLATFORM" == "opencode" && -f "$MCP_DST" ]]; then
+    oc_config_merge "$MCP_SRC" "$MCP_DST" "$MCP_DST"
+    info "Merged opencode.json (user config preserved)"
+  else
+    copy_if_changed "$MCP_SRC" "$MCP_DST"
+  fi
 fi
 
 # ── Summary ───────────────────────────────────────────────────────────────────

tests/adapters/opencode/config-merge.test.sh

@@ -0,0 +1,172 @@
+#!/usr/bin/env bash
+# Tests for adapters/opencode/config-merge.sh
+ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"
+source "$ROOT/adapters/lib.sh"
+source "$ROOT/adapters/opencode/config-merge.sh"
+
+test_oc_merge_fresh_install() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  rm "$existing"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  oc_config_merge "$built" "$existing" "$output"
+  local result=0
+  [[ -f "$output" ]] || { echo "output not created"; result=1; }
+  jq -e '.mcp.Gmail.url' "$output" >/dev/null || { echo "Gmail not in output"; result=1; }
+  rm -f "$built" "$output"
+  return $result
+}
+
+test_oc_merge_preserves_user_keys() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  cat > "$existing" <<'HEREDOC'
+{
+  "model": "anthropic/claude-sonnet-4-5",
+  "small_model": "anthropic/claude-haiku-4-5",
+  "mcp": {
+    "MyCustomServer": {
+      "type": "local",
+      "command": "my-server"
+    }
+  }
+}
+HEREDOC
+  oc_config_merge "$built" "$existing" "$output"
+  local result=0
+  jq -e '.mcp.Gmail.url' "$output" >/dev/null || { echo "Gmail missing"; result=1; }
+  jq -e '.model == "anthropic/claude-sonnet-4-5"' "$output" >/dev/null || { echo "model key lost"; result=1; }
+  jq -e '.small_model == "anthropic/claude-haiku-4-5"' "$output" >/dev/null || { echo "small_model key lost"; result=1; }
+  jq -e '.mcp.MyCustomServer.command == "my-server"' "$output" >/dev/null || { echo "user MCP server lost"; result=1; }
+  rm -f "$built" "$existing" "$output"
+  return $result
+}
+
+test_oc_merge_our_mcp_overwrites_same_name() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  cat > "$existing" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://old-url.example.com"
+    }
+  }
+}
+HEREDOC
+  oc_config_merge "$built" "$existing" "$output"
+  local result=0
+  local url; url="$(jq -r '.mcp.Gmail.url' "$output")"
+  [[ "$url" == "https://gmail.mcp.claude.com/mcp" ]] || { echo "our url should win: got $url"; result=1; }
+  rm -f "$built" "$existing" "$output"
+  return $result
+}
+
+test_oc_merge_detects_indentation() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  cat > "$existing" <<'HEREDOC'
+{
+    "model": "anthropic/claude-sonnet-4-5",
+    "mcp": {}
+}
+HEREDOC
+  oc_config_merge "$built" "$existing" "$output"
+  local result=0
+  grep -q '^    "model"' "$output" || { echo "expected 4-space indent"; cat "$output"; result=1; }
+  rm -f "$built" "$existing" "$output"
+  return $result
+}
+
+test_oc_merge_malformed_existing_falls_back() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  echo "this is not json" > "$existing"
+  oc_config_merge "$built" "$existing" "$output" 2>/dev/null
+  local result=0
+  jq -e '.mcp.Gmail.url' "$output" >/dev/null || { echo "fallback failed"; result=1; }
+  rm -f "$built" "$existing" "$output"
+  return $result
+}
+
+test_oc_merge_no_mcp_in_existing() {
+  local built; built="$(mktemp)"
+  local existing; existing="$(mktemp)"
+  local output; output="$(mktemp)"
+  cat > "$built" <<'HEREDOC'
+{
+  "mcp": {
+    "Gmail": {
+      "type": "remote",
+      "url": "https://gmail.mcp.claude.com/mcp"
+    }
+  }
+}
+HEREDOC
+  cat > "$existing" <<'HEREDOC'
+{
+  "model": "anthropic/claude-sonnet-4-5"
+}
+HEREDOC
+  oc_config_merge "$built" "$existing" "$output"
+  local result=0
+  jq -e '.model == "anthropic/claude-sonnet-4-5"' "$output" >/dev/null || { echo "model key lost"; result=1; }
+  jq -e '.mcp.Gmail.url' "$output" >/dev/null || { echo "Gmail not added"; result=1; }
+  rm -f "$built" "$existing" "$output"
+  return $result
+}